The present invention relates generally to the field of airbag modules and base plate attachments.
A conventional module for housing an airbag module in a vehicle has a cover or deployment door which attaches to a housing or base plate in which an air bag and inflator are housed. Commonly, a plurality of threaded studs extend from the base plate about its mouth and the cover has corresponding complementary holes which mate with the studs.
Conventional attachment designs may include rivets, rings, or rigid hooks to connect the base plate and cover. Other conventional airbag systems require the use of two separate base plates, which increase the costs associated with manufacturing the airbag system.
One drawback of such conventional designs is that the requirement of extra fasteners, rigid hooks or additional base plates increases the overall weight of the airbag module, cost and the difficulty in assembling the module.
Another drawback of using threaded studs to retain a cover to a base plate is that the studs can be inadvertently cross-threaded during assembly. The studs often require checking in order to verify proper assembly. Furthermore, the deployment of an airbag can be modified when the cover separates from the base plate during deployment, which varies the restraint performance from a designed and expected performance.
Additional drawbacks exist when utilizing fasteners to secure an air bag cover. For example, threaded fasteners are susceptible of loosening from vibration as a vehicle travels over a bumpy road and therefore require use of a thread binding agent or a lock washer to prevent loosening. This further increases the number of parts, complicates the assembly, and adds to cost and time required for assembly. As a result, such systems for attaching a cover to a base plate tend to be less feasible when constructing air bag modules for use in high volume and low cost applications.